Surgical scrub

ABSTRACT

VARIOUS CHEMICAL DISINFECTANTS CAN REDUCE BACTERIAL COLONIZATION FOR A BRIEF PERIOD OF TIME. HOWEVER EVEN BISPHENOLS OF THE HEXACHLOROPHENE TYPE AND IODINE WHEN INCORPORATED IN SCRUBS REMOVE ONLY PART OF THE TRANSIENT BACTERIA. OTHER TRANSIENT BACTERIA, ALONE WITH RESIDENT BACTERIA, REMAIN AND MULTIPLY WITHIN A FEW HOURS, SO THAT THE BACTERIAL FLORA BUILDS BACK UP. FOR HOSPITAL WORKERS, IT WOULD, THEREFORE, BE DESIRABLE TO HAVE A MORE EFFECTIVE SCRUB PRODUCT. THE SCRUB CONTEMPLATED HEREIN IS EFFECTIVE OVER A LONGER PERIOD THAN THOSE NOW KNOWN.

United States Patent Olhce 3,597,360 SURGICAL SCRUB Galen F. Collins, Bristol, Tenn, and Fred S. Barr and Charles F. Bullock, Bristol, Va., assignors to The S. E. Massengill Company, Bristol, Tenn. No Drawing. Filed May 2, 1968, Ser. No. 726,215 Int. Cl. Clld 3/48, 3/50 US. Cl. 252-106 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Much has been written about the bacteriology of the skin. In fact, one of the greatest factors in cross-infections is considered by many to be bacteria on hands. The transmitting of cross-infections by bacteria on hands has been found even greater than that by airborne bacteria or nasal Staph-carriers. Scrubbing with a soap reduces bacterial flora logarithmically, about one-half each six minutes. However it is well known that the use of a disinfectant in the soap reduces bacterial colonization in a briefer period of time and to a greater extent.

Since complete skin sterilization is not feasible, the importance of scrubbing preparations having both an antibacterial effect and a detergent elfect in reducing the number of bacteria on skin is well established, particularly for surgeons, obstricians, and examining physicians, as well as nurses and those applying therapy and dispensing food and medication. Numerous surgical scrub products are on the market, and most of these contain hexachlorophene or iodine bacteriostats in one form or another. However studies with hexachlorophene and iodine show that these scrub preparations lose their effectiveness in time, due to the build-up of bacterial flora, particularly when the scrubbed hands are gloved. Results obtained indicate that within three hours after washing with these soaps the antibacterial effect disappears. This is especially significant in view of the fact that one-third of surgical gloves are punctured during the course of an operation.

SUMMARY OF THE INVENTION Since hexachlorophene and iodine scrubs have very little bactericidal effect at the end of three hours, it has been proposed that some antibacterial procedure be adopted by surgeons and attending nurses after two hours, for instance a seventy percent alcohol rinse, and a change to new gloves.

According to the practice of this invention such measures would not be necessary. An antibacterial skin disinfectant is provided by which an unusually low bacterial 3,597,360 Patented Aug. 3, 11971 flora is maintained even after three: hours of Wearing surgical gloves. The disinfectant is in the form of a liquid or solid soap formulation containing a detergent and a bacteriostat. Bacteriostasis is produced herein by nitromersol.

DETAILED DESCRIPTION OF THE INVENTION Various chemical disinfectants can reduce bacterial colonization for a brief period of time. However even hisphenols of the hexachlorophene type and iodine when incorporated in scrubs remove only part of the transient bacteria. Other transient bacteria, along with resident bacteria, remain and multiply within a few hours, so that the bacterial flora builds back up. For hospital workers, it would, therefore, be desirable to have a more effective scrub product.

The fact that the scrub contemplated herein is effective over a longer period than those now known is quite surprising in view of in vitro tests which show very little bactericidal difference between nitromersol and other organomercurial antimicrobials. Equally surprising is the fact that nitromersol by itself is effective in maintaining a low bacterial flora. As shown in our copending application filed concurrently herewith, combinations of diphenyl and organomercurial antimicrobials maintain a low bacterial flora for over three hours whereas antimicrobials alone do not. Nitromersol, however, has been found to be an exception.

Broadly the invention contemplates the use of nitromersol in a liquid or solid detergent to form a soap for topical use. However the detergent-antimicrobial composition will generally include skin conditioners and the like. For the purpose of illustration a desirable liquid base formulation is set forth in Example a. The base contains a highly concentrated, neutral, anionic synthetic detergent whose active ingredient is a modified lauryl sulfate plus an amide builder. Additionally included is a neutral, essentially nonionic, self-emulsifying, fatty-based ester derived from glycerides and particularly suited for handwashing preparations. Lanolins can also be incorporated in liquid scrubs, so modified that they are water soluble, essentially nonionic detergents. Polypropylene glycol and perfume can also be used in liquid scrubs as illustrated herein.

This invention can perhaps best be illustrated by comparative examples. In these examples, compositions as well as bacterial counts before and after scrubbing are given. To determine its effectiveness in reducing the number of bacteria on hands, the base as well. as antibacterial detergents were tested using a slightly modified standard procedure. The right hand of each subject was placed in a sterile 1000 m1. plastic bag and 300 ml, of sterile 0.85% saline was added. The hand was shaken vigorously for three minutes. Following the shaking process, the bacterial counts were run by standard methods, diluting the saline and plating in petri dishes with MPH Medium (BBL). The plates were incubated at 37 C. for 72 hours. The number of bacteria per hand (per 300 ml.) are reported. Following the initial count, the hands were scrubbed for 4 minutes with the test products, followed by rinsing in tap water. When the scrub was completed the right hand was placed in a rubber glove and a bacterial count was conducted on the left hand. The right hand was allowed to remain in the glove for three hours and then a bacterial count was conducted on it.

3 4 Example a Percent Part I: Percent Subject Pro-scrub Post-scrub reduction Alkyl sulfate 18-5 1 7 10 100 Alkanolamide 4.5 735E100 5.4 10e 3g Unsulfatcd alcohol 0.6 4 g: 8 igg Ammonium sulfate 0.5 5 13 s 10 0 100 Ammonium chloride 0.5 Denatilreq ethyl alcohol. 'T".'""." Organic mercurial antimicrobial agents are well known. of 1110150, and mglycndes Wlth 10 Hence the preparation or other source of nitromersol a nomomc emulsifier i (metaphenC H HgNO need not be discussed. l Ior- Water Soluble Polyoxyal y am) m mally the scrubbing composition, regardless of ingredients Propylene glycol other than the detergent, will contain 0.01 to 1 percent, Perfume preferably 0.1 to 0.5 percent, nitromersol by weight based 46 7 on the composition.

' As indicated hereinbefore, reductions of bacterial flora immediately after scrubbing are virtually the same when Part 53 3 the organomercurial and bisphenolic antimicrobials are Water used. However they do not hold the count down. This 100 00 will be apparent from Table I wherein hexachlorophene (HEXA), henylmercuric acetate (PMA), and other an- Procedure.The ingredients in Part I on a weight basis timicrobials are compared after gloves are worn three are combined and heated to 60 C. to 70 C. using a hours. Averages of at least five determinations are given.

TABLE I Bacterial count after scrub Bacterial count after three hours in glove Pre-scrub Post-scrub Percent Pre-scrub Post-glove Percent Active ingredient count count change count count change 3. 86 10 1. 08x10 97 3. 86X10 8. 56x10 +221 4.1 10 1. 56X105 96 4.1 10 2. x10 46 8. 5x10 2. 29x10 73 8. 5x10 9. 3x10 +109 1. 77x10 2. 38X105 87 1.77Xl0 1. 46 l0 17 Nitromersol 4. 87x10 1. 025x10 78 4. 87x10 1. 24 1u 75 water bath and stirring means to make a solution. The water, Part H, is then slowly blended in, the composition being gently agitated to prevent incorporation of air into the product.

Percent Subject Pre-scrub Postscrub reduction Average. 5. 77x10 8. 0x10 95 When antimicrobials are incorporated in the base, a portion of the water is replaced thereby. Thus if 0.3 percent antimicrobial is incorporated in the base, Part II will be 53.0 percent Water.

Procedure.-After the blend is formed in accordance with Example a, the nitromersol is added at the 60 C. to 70 C. elevated temperature. Following Example a the water is then incorporated in the composition.

Whereas hexachlorophene reduces the bacterial count 97 percent after the scrub, the duration of the effectiveness is short. After the glove has been on the hand three hours the count is 221 percent higher than it was prior to the scrub. Phenylmercuric acetate (PMA) is somewhat more effective, the reduction in bacterial count being 96 percent post-scrub, but only 46 percent at the end of three hours. However the reduction in bacterial count after three hours is still 75 percent in the case of nitromersol.

The fact that nitromersol maintains a low bacterial flora on the skin was also unexpected in the light of in vitro work with the antimicrobials. As will be seen in Table II there is very little difierence in in vitro activity between the bisphenolic and organomercurial antimicrobials.

The in vitro work with these products was carried out against Candida albicans and Staphylococcus aureus by a tube dilution method. The products were diluted in a 50-50 alcohol-Water mixture. This was then serially diluted through sterile Trypticase Soy Broth in 18 x mm. tubes. After the dilution the tubes were heated to 70 C. for 1 hour to insure sterility. When the tubes had cooled to room temperature they were inoculated with 0.1 ml. of one of the test organisms. To prepare the test organism wash an 18 to 20 hour culture from an agar slant with sterile 0.85% saline and dilute with sterile saline until there is 50 percent light transmission at 550 my wavelength on the Spectronic 20 Colorimeter. As stated earlier 7 0.1 ml. of this saline suspension is used on the inoculum for each tube. The tubes were then incubated at 37 C. for 24 hours and the dilution showing no visible growth is reported as the maximum inhibitory dilution (M.I.D.).

TABLE II.MAXIMUM INHIBITORY DILUTION NOTE.-NI=NO inhibition.

TABLE III Pie-scrub Post-glove Percent count count change Composition:

513, 000 460, 000 -9. 5 2,174,400 1, 611, 600 -25.7 Nitromcrsol 1. 08 10 1 24x10 75 The foregoing demonstrate that this invention results in a highly effective surgical scrubbing composition.

It is thus apparent that an antibacterial skin soap is provided herein which is eminently suited for hospital use. Various detergents can be used, either natural or synthetic, and either nonionic or anionic. Desirable anionic detergents are surfactants such as alkali alkyl sulfates, alkylaryl sulfonates and fatty acid salts. Examples are sodium cholate, sodium oleate, sodium stearyl sulfate, sodium lauryl sulfate, glycerol monosterate, methyl phenyl sulfonate, propyl phenyl sulfonate, and potassium lauryl sulfate. Among the nonionic surfactants are the polyoxyethylene fatty acid derivatives and sorbitan derivatives. Examples are polyoxyethylene sorbitan, polyoxyethylene monooleate, polyoxyethylene monostearates, nonylphenoxy polyethers and octylphenoxy polyethers each having three to thirty polyether or polyoxyether groups, as well as sorbitan monostearate, sorbitan sesquioleate, and sucrose and lanolin esters. As indicated hereinbefore the detergent compositions of this invention can be either liquid or bar soaps. To illustrate the use of a bar soap, the following example is given.

6 Example Scrub Bar Formulation Composition: Percent Combination of mono, di, and. triglycerides with a nonionic emulsifier 13.0 Laurie Diethanolamide 13.0 Water soluble polyoxyalkylene lanolin 7.0 Nitromersol 0.05

Triethanolamine Lauryl Sulfate, Anhydrous 44.0 Magnesium Trisilicate 5.0 Corn Starch 18.0

Procedure.-A liquid blend is formed from the glycerides, lauric diethanolamide and polyoxyethylene lanolins I) by heating the mix at a temperature of 70 C. to 80 C.

One by one, at the elevated temperature, the nitromersol and triethanolamine lauryl sulfate are dissolved in the blend. After these are put in solution the magnesium trisilicate and corn starch are blended in and the blend is poured into bar forms to cool.

Post-scrub and post-glove results obtained by the use of this bar soap are equivalent to those obtained with the liquid scrub disinfectant of Example b.

In addition to the detergent, any of the known skin 0 conditioners, perfumes, colorants, and the like can be incorporated in the liquid or bar soap composition. Such modifications and variations will be obvious to those skilled in the art. Hence such ramifications and variations are within the scope of this invention.

What is claimed is:

1. As an antibacterial skin disinfectant, a surgical scrub consisting essentially of a detergent and an organomercurial bacteriostat rendering the surgical scrub capable not only of reducing bacterial flora but of maintaining a low bacterial flora on the skin, the detergent being selected from the group consisting of nonionic and anionic surfactants, the organomercurial bacteriostat being nitromersol, the surgical scrub containing 0.01 to 1 percent nitromersol by weight based on the composition.

2. The disinfectant of claim 11 wherein the surgical scrub is in liquid form, containing 0.1 to 0.5 weight percent nitromersol.

3. The disinfectant of claim 1 wherein the surgical scrub is in bar form, containing 0.1 to 0.5 weight percent nitromersol.

References Cited UNITED STATES PATENTS 1,630,072 5/1927 Raiziss 260-433 r0 1,893,248 1/1933 Sander 260-433 0 FOREIGN PATENTS 3/1935 Great Britain 252-107 LEON D. ROSDOL, Primary Examiner P. E. WILLIS, Assistant Examiner US. Cl. X.R. 252 407; 424 291 

